Finding the Fourth Proportional to 1,379.24, 1,902.88 and 789.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,379.24 : 1,902.88 = 789.56 : x
2. Step 2: Convert to fraction form
   1,379.24/1,902.88 = 789.56/x
3. Step 3: Cross multiply
   1,379.24x = 1,902.88 × 789.56
4. Step 4: Simplify right side
   1,379.24x = 1,502,437.93
5. Step 5: Solve for x
   x = 1,502,437.93/1,379.24
6. Step 6: Final answer
   x = 1,089.32